Orchard Park, N.Y. — For all of the uncertainty surrounding the Buffalo Bills' offense heading into the 2014 season, the Bills' defense should continue to be the strength of the team.

Buffalo's success on defense in 2013 started with the defensive line, which has developed into one of the most talented units in the AFC. Mario Williams is the highest paid defensive end in the NFL, and he plays up to that price tag. Last season, Williams had 13 sacks and 48 quarterback hurries.

Williams wasn't the only one doing damage, though. Jerry Hughes surprised everyone by piling up 10 sacks, while Kyle Williams had 10.5 sacks and Marcell Dareus had 7.5. Buffalo ended up second in the NFL with a franchise-record 57 sacks in 2013.

Can they match that type of production after losing defensive coordinator Mike Pettine to the Cleveland Browns? That's one of the key things to watch for with this defensive line in 2014.

1. How will the Bills' pass rush change under new defensive coordinator Jim Schwartz?

While Pettine's defense was a blitz-heavy scheme that utilized a lot of 3-4 principles, new defensive coordinator Jim Schwartz can be expected to have the Bills playing a defense that more closely resembles a traditional 4-3.

The roles of the defensive linemen shouldn't change drastically, and all four of the Bills' expected starters fit into a 4-3 defense just fine. The question worth asking is whether or not the Bills will be quite as aggressive when it comes to generating pressure under Schwartz, who traditionally hasn't utilized the blitz as often as Pettine did a year ago.

2. Will Marcell Dareus be available for the entire season?

Dareus has proven to be worth the No. 3 pick the Bills spent on him in the 2011 NFL Draft when he's been on the field. The problem is Dareus has run into some trouble off the field and also struggled with injuries in his career.

This offseason, Dareus has had two run-ins with the law, once for drug charges in Alabama and a second time for crashing his car in a drag-racing incident. Dareus was a full participant at minicamp after missing OTAs, but whether or not he will be available when the season starts is another issue. Alan Branch provides some depth at defensive tackle, but Dareus is one of the stars of Buffalo's defense.

3. Can Jerry Hughes maintain his production?

Hughes was considered to be a bit of a bust up until his 10-sack season in 2013. Prior to last season, Hughes had five career sacks in three years with the Colts. The Bills helped turn him into a productive player, but has he truly turned the corner or was he just the right fit for Pettine's scheme? If Hughes proves he can string together another solid season in Buffalo, he could be in for a raise on his next contract.